The following assert getting hit randomly while running the rollback_fuzzer_unclean_shutdown test.

        WT_ASSERT(session,
          (newer_hs_ts == WT_TS_NONE || hs_stop_ts <= newer_hs_ts || hs_start_ts == hs_stop_ts));

The values of the variables in the assert statement are:
newer_hs_ts - 6810105723700117506
hs_start_ts - 6810105723700117506
hs_stop_ts - 6810105723700117509

From the above values, it seems that the order of the updates in the update chain before inserting them into the history store should be something like the following.

update(6810105723700117506) -> Tombstone(6810105723700117509) -> update(6810105723700117506)